It is narrated from Ata that Ibn Abbas and Ibn al-Zubair (may Allah be pleased with them) said regarding a woman who has taken khul‘ and then her husband divorces her: "She does not need a divorce, because the husband has divorced one who is no longer his wife."
Hadith Referenceمسند الإمام الشافعي / كتاب عشرة النساء والإيلاء والخلع / 1236
Hadith Takhrijاسناده قوى ولا تضر عنعنة ابن جريج عن عطاء اخرجه البيهقي: 317/7 - وفي المعرفة السنن والآثار له (4400) - وعبدالرزاق (11772) وابن ابي شيبة (18488)۔